Method for separating substances



Aug. 23, 1932. L. D. JONES METHOD FOR SEPARATING SUBSTANCES Original Filed April l5, 1925 Patented Aug. 23,' 1932 UNITED s'rA'ri-:sv vra'rls;1--l'r .ora-ics 4lll-il() D. JONES, 0F PHILADELPHIA, llf'ENNsYLvANl'A.- ASSGNOR TO THE SIIABPLES- SPECIALTY COMPANY, F IHILADELPHA, PENNSYLVANIA, A CORPORATION 0F DELAWARE METHOD FOR SEPABATING SUBSTANCES Application filed April 13, 1925, Serial No. 22,727. :Renewed February 17, 1932.

My invention relates toa method forseparating substances and particularly to the removal of impurities from a substance.

In the centrifugal separation of substances 5 into their constituents and inthe centrifugal clarification of substances, a. substance or a constituent of a substance that is discharged from the centrifugal machine may contain a liquid impurity that is either in solution or lo suspension and it may also contain a gaseous impurity that is in solution or in suspension. Such a liquid impurity may be of such a nature that even though it is in solution when the substance is discharged from A'thecentrifl5 ug'al machineit will precipitate out, for example, When the substanceis cooled.l Such a gaseous impurity may be in solution or, particularly if the substance is very viscous, it may be in suspension. While steps might be taken with the intention of removing such impurities at the same time that the centrifugal separation or clarification is beingcarried on the practical performance of such steps is in most cases impossible of accom- .25 plishment because of the conditions under which the centrifugal separationl or clarification is carriedvout. In the puricationand renovation of oil that is intended for useras an insulating' medium, for example, for the submersion of high tension electric switchesA contain dissolved water that will be .precipi-, tated outwhen the oilis cooled and the oil 40 will also contain dissolved gases, some of which gases are mtroduced into 1t when 1t1s dischargedin the finely divided state from the bowl of the centrifugal separator orl clarifier.

It is an object .of my invention to' p}ovide '45 a. process whereby impurities remaimng 1n a substance after` it has been treated a centrifugal separator or clarifier may be re moved therefrom. i

In accordance with my invention a sub-l stance that has been treated in a centrifugal separator or clarifier is `vsubjected to reduced pressure, i. e. a. pressure below that under which'it was subjected to the centrifugal separating or clarifying operation, and is mainpressure is carried to such a point that dis-- solved or suspendedgaseous impurities will be withdrawnand if dissolved liquid impurities are present the pressure isreduced belowv Vthat at which the impurities, that are atthe temperature of the substance being treated,

insulating oil treatment in a. centrifugal separator or clarifier will leavein the oil some dissolved water, a part of which would pre-l cipitate out upon cooling' of-thev oil. and in some cases a trace of suspended water,.and

also dissolved gases, some of said gasesl having possibly been introduced when the oil was discharged in afinely divided state from the centrifugal machine. The oil 'that has been treated in the centrifugal separator or miwill boil and .pass olf. 'l In thepurifica'tion of clarifier is then subjected to pressurethat is v so reduced that dissolved gases will be withfao drawn and so reduced that -it is below the pressureat which water and other impurities at the temperature of 'the oil will boil .and

pass off. -In other words bymy process im-v miscible impurities that cannot removed by' or that may have been introduced as a consequence fof centrifugal separation or purliication may be removed, such a high degree of purification being particularly desirable when.. the impurities are likely tol assume a 'different stateA or condition or likely to produce unn desirable effects under changes of pressure or temperature of the purified substance.

In accordance with my'inventiongaseous impurities that'are in solution as well as gaseous impurities that are cntrappcd and become suspended in a. substance when itis dischargedfrom a centrifugal separator or' i clarifier,'as in" the caseof the centrifugal separation or clarification of gum arabic and sugar solution, may be readily removed.

In'tlie single figure -of the drawing I have shown `diagrammatically apparatus embodyy ing and whereby my invention may be prac- VReferring tothe draw-ing, the centrifugal separator or clarifier 1 is fed throufrh the pipe 2'with a substance to be centrifii'gally clarified or separated. If a separation'occurs impurities may be discharged through the usual outlet 3 and thesubstance to be purified is discharged through the usual outlet 4. vThe substance is collected in the tank 5 having an outlet pipe 6 controlled by the float valve 7 The outlet pipe 6 leads into a vacuum cnamber 8 that may be ofany desired form, prefferably a form that will provide a circuitous and indirect path of flow for the substance.

Vacuum is maintained within the chamber 8 by means of a vacuum pump 9 preferably `connected to the tank 8 at vthe upper portion thereof as by the pipe 10. The-substance to be purified is withdrawn from the vacuum chamber 8 through the pipe 11, the outiiow of the substance from the vacuum chamber being -controlled by the float valve- 12, and effected by pump 11.

The vacuum maintained .by the pumps 9 and 11 operating together or separately will be suiiiciently highto cause evaporation of the impurity to. be removed at the tem )erature at which that impurity exists. I the temperature of the liquid substance entering the tank S is high, for example, 145 F., then the pump or pumps will have to produce a vacuum'high enough to cause the impurity [sought to be removed to evaporate at that centrifuge. Heater 13 may be provided with temperature. As a particular instance I vwould mention that in the purification of oil the oil entered the vacuum` tank at 140? F. anda vacuum of.291/2 inches offmercury (approximately 1/2 inch of mercuryabsolute pressure) -was maintained within the tank.

In order that it will not be necessary to main.-

tain too high a degree of vacuum in the tank 8 the 'substance entering the tank 8 may be heated as by heater 13 up to a higher tcmperature than that4 at which it leaves- 'the any suitable source of heat supply such as a steam inlet 20 and an outlet 21. If water is to be removed from oil either the temperature within the tank 8 or the degree of vacuum within the tank ,8 or both .temperature 'and vacuum are preferably slightly hi her than would be n eccssary'to cause water iat is not Vdissolved in or mixed with oil to evaporate.

While I have described my invention with reference to particular substances and apparatus I do not intend that my invention shall be-limited 'to the details referred to but intendthat it shall include such variations and modifications as fall within the hereunto appended claims. v

What I claim and desire to secure by Letters Patent of the United States is 1. The process of purifying oil that contains impurities including dissolved and sus-'pV pended water 'and that has a vapor pressure not substantially higher than the vapor pressure of water under temperature and pressure conditions at which water will vaporize from the oil, and thereby producing oilgsubstantially free of suspended and dissolved water and gases for uscs'in which suspended and dissolved. water andgas impair theeffeet and stability of the oil, which comprises centrifugally separating immiscible impurities from the oil while it is heated to la suf-v ficiently high temperature to reduce itsviscosity, and Vthen subjecting .the centrifuged oil without substantial reduction in temperature toa pressure sufficiently low toeifect removaltherefrom in the form of vapor or gas of dissolved water and gaseous impurities vthat exist in the oil after the centrifugal separating step, While maintaining the temperatureV and pressure at such values that vaporization' of the oil is substantially avoided.

ties from the oil while it is` heated to a suiliciently high temperature to reduce its viscosity.' and then subjecting the centrifuged oil to such conditions of temperature and pressure as will cause-.dissolved water 'f and gaseous impurities that exist in the oilafter the Acentrifugal separating step to pass oit' as vapors and gases,"while maintaining the vtemperature and pressure at such values as tol avoid substantial loss of yor injuryto the o1 3. The proce of purifying oil that conv tains dissolved and Asuspended water, and that has 'a vapor pressure not substantially higher than thevapor lpressure of water. under temperature fand pressure conditions at` which water will Vvaporizc from the oil, and thereby producing oil substantially. free of suspended 'and dissolvedwater and. gases for uses in which such mpurities impair the eifect and stability of he oil, which comprises centrifugally sepaating immiscible impurities from the oil vhile it is heated to a sufficiently high temerature to reduce its viscosity, and then subecting the centrifuged oil in a heated state o a pressure lower than the pressure ,t which it was centrifugally treated md sultlcently low to effect removal herefrom in the form of vapor or gas of lissolved water and gaseous impurities that :xist in the oil after the centrifugal separatng step, while maintaining the temperature md pressure at such values as to avoid sub- ;tantial loss of or injury to the oil.

4. The process of purifying oil that con- :ains impurities of thecharacter that impairs :he value of the oil for electrical insulating 1nd dielectric use including suspended and lissolved Water, and thereby producing oil for use as electrical insulatingr or dielectric )il and which is substantially free of dissolved Water and gas,'which comprises centrifugally separating immiscible impurities from the oil while it is heated to a suiiiciently high temperature to reduce its viscosity, and then subjecting the centrifuged oil to such conditions of temperature and pressure as will cause the removal therefrom in the form of vapor or gas of dissolved water and gaseous impurities that exist in the oil after 'the centrifugal separating step, while maintaining the temperature and -pressure at such values as to avoid substantial loss of or injury to the oil.

5; The process of purifying oil that contains impurities of thev character that impairs the value of the oil for electrical insulating and dielectric use includingr suspended and dissolved water, and thereby producing oil for use as electrical insulating: or dieleetrie oil 'and which is substantially free of dissolved water and oxygen, which comprises centrifugally separating immiseible impurities from the oil while it is heatedl to a sufliciently high temperature to reduce its viscosity, and then subjecting the centrifuged oil to such conditions of temperature and pressure as will cause the removal therefrom in the form of vapor or gas of dissolved Water and oxygen that exist in the oil after the centrifugal separating step, while maintaining the temperature and pressure at such and suspended and dissolved water and gas impair the cil'ect .and stability of the oil, which comprises centrifugally separating immiscible impurities including solid particles and water from the oil While it is heated to a suflicently high temperature to reduce its viscosity, and then subjecting' the centrifugal oil to such conditions of temperature and pressure as will cause dissolved water and gaseous impurities that exist in the oil after the centrifugal separating step to pass oi as vapors and gases, while maintaining the temperature and pressure at such values as to avoid substantial loss of or injury to the oil.

In testimony whereof, I have signed my name tothis specification.. l

LEO D. JONES.

values as to avoid substantiallloss of or injury to the oil.

6. '1 he process of purifying oil that-contains impurities including dissolved and suspended 'water and solid particles and that has a vapor pressure not substantially higher than the vapor pressure of water under temperature and pressure conditions at which water will vaporize from the oil, and thereby producing oil substantially free of solid particles and of-suspended and dissolved water and gases for uses in which solid particles 

